Potassium and Its Disorders

Abstract

Potassium is the major intracellular cation in the human body. Over 98% of the total body potassium is located within the intracellular compartment. In healthy adults, the total intracellular content of potassium is equivalent to 3000–3500 mmol. Approximately 70% of this amount is found in skeletal muscle with lesser amounts in bone, red blood cells, liver and skin. The extracellular compartment contains 1–2% of the total body potassium. This uneven distribution of total body potassium is the result of an electro-genic pump, Na + , K + ATPase. This pump transports three sodium ions extracellularly in exchange of transporting two potassium ions intracellularly. This mechanism cre- ates a ratio that determines the cell membrane potential. Maintenance of this potassium ratio and membrane potential is vital for normal nerve conduction and muscular contraction. potassium redistribution from intracellular fluid to extracellular fluid and imbalances between potassium intake and excretion.